Masterwort Appearance

A few years ago I purchased a package of masterwort seed from you, after hearing of masterwort on a gardening show (I believe it was "The Canadian Gardener"). I planted the seeds as it said on the package and eight months later they started to grow. Last year was their first season outside. They have wintered nicely, at least something which I think is masterwort wintered nicely. I live in Calgary, Alberta, Canada which is zone 3. The catalogue says zone 5 to 7 for the plant so this is not too bad I'd say.
What I have been unable to find out is more information on what to expect of the plant. Would you be able to tell me the mature height and spread of this plant? Also, what are the flowers like?

The plant reaches a height and spread of 60 by 60 centimeters. It belongs to the carrot family and has cut leaves and its flowers are white topped flat compound umbels.